One fine sunny Sunday afternoon, Mr and Mrs Lee took their sons, Jacky and Paul, to a picturesque seaside to have a picnic. As the seaside was far away from their home, Mr Lee drove them there.

When they arrived at their destination, Jacky and Paul were too impatient to wait, so they took their swimsuits and rushed into the changing room to change. After that, they hopped into the sea. In the meantime, their parents laid the mat with fried rice, two bottles of Sprite, a chocolate cake and some sandwiches. Mr Lee then tuned the radio to class 21 for his wife. Meanwhile, Mrs Lee went to buy a newspaper for her husband. While Mr Lee read the newspaper, his wife listened to the radio.

After about twenty minutes, the two boys were hungry and went back to the beach to have some food. They ate the delicious fried rice before eating the sweet chocolate cake and sandwiches which were prepared by Mrs Lee. Jacky liked the taste of the cake and sandwiches and asked his mother, “How delicious! How did you do it?” Mrs Lee answered, “I used some baking powder and some fragrant ingredients. Mr Lee also joined in praising Mrs Lee for giving them such palatable food.

After their meal, it was half past six and Mr Lee suggested going home. They packed up and were soon on their way home. Mrs Lee promised to take them to the beach again. The children were happy on hearing that. They are now looking forward to the next trip.

Your English is fine. Perhaps working on your narrative technique will help make the story more lively.

One fine sunny Sunday afternoon, Mr and Mrs Lee took their sons, Jacky and Paul, to a picturesque seaside to have a picnic. AsThe seaside was far away from their home, so Mr Lee drove them there. (Doesn't read well with two sentences starting with when and as next to each other)

When they arrived at their destination, Jacky and Paul took their swimsuits and rushed into the changing room to change. After that, they hopped into the sea. (Talk about their swim) In the meantime, their parents laid the mat with fried rice, two bottles of Sprite, a chocolate cake and some sandwiches. Mr Lee then tuned the radio to class 21 for his wife. Meanwhile, Mrs Lee went to buy a newspaper for her husband. While Mr Lee read the newspaper, his wife listened to the radio. (Why did they do that? They could read newspaper and listen to the radio anywhere)

After about twenty minutes, the two boys were hungry and went back to the beach to have some food. They ate the delicious fried rice before eating the sweet chocolate cake and sandwiches which were prepared by Mrs Lee. Jack liked the taste of the cake and sandwiches and asked his mother, “How delicious! How did you do it?” Mrs Lee answered, “I used some baking powder and some fragrant ingredients." Mr Lee also joined in praising Mrs Lee for giving them such palatable food. (strange way of putting it, given the tone of the story)

After their meal, it was half past six and Mr Lee suggested going home. (They only stayed for 20 minutes and it's 6:30!) They packed up and were soon on their way home. Mrs Lee promised to take them to the beach again. The children were happy on hearing that. They are now looking forward to the next trip.